BASIC CONCEPTS This chapter will focus on the details of coronary angiographic anatomy and the requirements for optimal angiographic visualization of coronary arterial lesions.
The coronary arterial segments need to be visualized in two orthogonal angiographic views, each segment of interest aligned perpendicular to the x-ray beam to avoid the problem of vessel foreshortening. Orthogonal views help to ensure that eccentric or “ribbon-like” coronary lesions are not missed or underestimated by only visualizing the “wide”and not the “edgeon” view of the contrast filled arterial lumen. Overlap with other vessels and the proximal portion of branches from the segment being visualized needs to be avoided to prevent either obscuring true lesions or creating artifacts from edge effect which can simulate lesions.The coronary vessels curve throughout their course. This requires different projections for proper visualization of each portion of the vessel. The heart lies obliquely in the chest with a great degree of variability from individual to individual in its orientation of the reference planes-frontal (or coronal), sagittal, and transverse. Therefore, implicit in the following discussions of the “best view or angle” for each major segment is the understanding that these are the “average or usual” best views and must be individualized based on the individual patient's anatomy and confirmed with a second orthogonal view.These will be summarized in Table 1.